I have two hard drives i want to make raid of them but i don't know that how to physicaly connect them and which software is required so i need a tutorial that tell me how to make disk raid starting from the scratch.

You can keep your connection as such for the software RAID.
Which distirbution are you using?
If you are using SUSE, goto YAST and make 2 parttions as Linux RAID.
Then select "Create RAID" . Add these 2 RAID partitions.

You have to choose what kind of RAID you want?
Since you have 2 harddisks you can choose RAID0 (improves performance)
or RAID1 (mirroring).

now a new device /dev/md0 will be created. Mount it.
Your RAID is ready!

After rebooting I faced some problems with SUSE 9.2 . I am trying to solve it now.
let me know if this works...

isn't there a raid controller required in this case?

No hardware Raid controller is required for linux software raid. As long as linux can see the drives, they can be set up as a software Raid.